Roller formed hydraulic variable cam timing phaser

ABSTRACT

Roller forming portions of the VCT phaser to join the sprocket housing of the phaser to the end plates provides a reduction in oil leakage from the phaser as well as less distortion of the end plates of the phaser. Furthermore, by roller forming the sprocket housing of the VCT phaser to secure the end plates to the sprocket housing, the total number of parts needed is reduced, and the total number of holes needed to be drilled is reduced, reducing the overall cost of the phaser.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Patent Application No.62/398,237 filed on Sep. 22, 2016, the disclosure of which is hereinincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The invention pertains to the field of roller forming. Moreparticularly, the invention pertains to roller forming a portion of thehydraulic variable cam timing (VCT) phaser or an electric phaser(e-phaser).

SUMMARY

Roller forming portions of the VCT phaser to join the sprocket housingof the phaser to the end plates provides a reduction in oil leakage fromthe phaser as well as less distortion of the end plates of the phaser.Furthermore, by roller forming the sprocket housing of the VCT phaser tosecure the end plates to the sprocket housing, the total number of partsneeded is reduced, and the number of holes needed to be drilled isreduced, reducing the overall cost of the phaser. Additionally, theoverall package is reduced since a snap ring is not needed and theprocess of joining the sprocket housing of the phaser to the end platesby roller forming or orbital riveting replaces at least one weld, whichcan cause distortion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows perspective view of a phaser prior to roller forming.

FIG. 2 shows a sectional view of FIG. 1 along line 2-2.

FIG. 3 shows a detail of area A of FIG. 2 prior to roller forming.

FIG. 4 shows a perspective view of the phaser after roller forming.

FIG. 5 shows a sectional view of FIG. 4 along line 5-5.

FIG. 6 shows a detail of area B of FIG. 5.

FIG. 7 shows a close up of an example of possible geometry of the endplate and the sprocket housing prior to roller forming.

FIG. 8 shows a close up of the same example of possible geometry of theend plate and the sprocket housing of FIG. 7 after roller forming.

FIG. 9 shows an exploded perspective view of the sprocket housing and anend plate pre-roll forming.

FIG. 10 shows a perspective view of the sprocket housing with an endplate pre-roll forming.

FIG. 11 shows a front view of the sprocket housing and end platepre-roll forming.

FIG. 12 shows a cross-section along line 12-13 prior to orbital rivetingtaking place.

FIG. 13 shows a cross-section along line 12-13 prior to roller forming.

FIG. 14 shows an exploded perspective view of the sprocket housing andan end plate post-roll forming

FIG. 15 shows a detailed close up of area C of FIG. 14.

FIG. 16 shows a perspective view of the sprocket housing with an endplate post-roll forming.

FIG. 17 shows a detailed close up of area D of FIG. 16.

FIG. 18 shows a front view of the sprocket housing and end platepost-roll forming.

FIG. 19 shows a cross-section along line 19-19 of FIG. 18.

DETAILED DESCRIPTION

FIGS. 1-6 show a phaser prior to and after roller forming the sprockethousing 10 to secure the end plates 12, 18 to the sprocket housing ofthe VCT phaser 8. The VCT phaser 8 may be a hydraulic phaser or anelectric phaser. It should be noted that the rotor 14 and the oilcontrol valve 16 of the phaser 8 are present in FIGS. 1-3, but have beenremoved from FIGS. 4-6 for clarity purposes. While FIGS. 4-6 show onlyone of the end plates 12 being captured by roller forming, the processwould be repeated on the other side of the sprocket housing. Inpreferred embodiments, both sides of the sprocket housing 10 are rollerformed to complete the assembly of the phaser 8.

The sprocket housing 10 has sprocket teeth 9 around an outercircumference thereof. The housing also has counterbores 11, 13 oneither side of the sprocket housing 10. The counterbores 11, 13 of thehousing 10 receive end plates 12, 18. The counterbores 11, 13 arepreferably an internal step cut into the internal diameter 10 a of thesprocket housing 10. The counterbores 11, 13 do not interfere with therotor 14 or oil control valve 16. The end plates 12, 18 may be pressedinto the counterbores 11, 13 until the end plates 12, 18 are flush withthe counterbore 11, 13.

When the end plates 12, 18 are present in the counterbores 11, 13 of thesprocket housing 10, prior to roller forming, the edges on each side ofthe sprocket housing 10 form a lip or flange 15 which axially extendsfurther than the end plates 12, 18 as shown in FIGS. 2 and 3.

The lip or flange 15 of the sprocket housing 10 undergoes continuousbend (roller forming) until the lip 15 captures the recessed end plate12, 18, retaining the end plates 12, 18 to the housing 10 as shown inFIGS. 5-6.

By retaining the end plates 12, 18 to the sprocket housing 10 throughroller forming, the amount of end plate 12, 18 distortion is lowered andthe oil leakage from the phaser 8 where the end plates are joined to thesprocket housing 10 is reduced. Additionally, the holes, tapped holes,and bolts needed to ordinarily fasten the end plates to the sprockethousing are eliminated. The overall package of the phaser is smalleralso. Welding of the end plates 12, 18 to the sprocket housing 10 canalso be eliminated. Furthermore, the end plates 12, 18 may be thinnerand lighter.

FIGS. 7-8 show a close up of an example of possible geometry of the endplate and the sprocket housing prior to roller forming and after rollerforming has taken place, respectively.

FIGS. 9-17 show a schematic of an alternate embodiment of securing theend plates 112, 118 to the sprocket housing 110 via orbital riveting,with FIGS. 9-13 showing the phaser 108 prior to orbital riveting andFIGS. 14-17 showing the phaser 108 after orbital riveting. The phaser108 may be a hydraulic phaser or an electric phaser.

It should be noted that the rotor 114 and the oil control valve 116 ofthe phaser 108 are not present in the drawings for clarity purposes. Inaddition, while FIGS. 9-10 show one of the end plates 112 being capturedby roller forming, the process would be repeated on the other side ofthe sprocket housing. The end plates 112, 118 and counterbore 111, 113for the other side of the sprocket housing have references numbers butare not shown in the Figures. In preferred embodiments, both sides ofthe sprocket housing are roller formed to complete the assembly of thephaser 108.

The sprocket housing 110 has sprocket teeth 109 around an outercircumference thereof. The housing also has counterbores 111, 113 oneither side of the sprocket housing 110. The counterbore is an internalstep 111, 113 cut into the sprocket housing 110. The counterbores 111,113 of the sprocket housing 110 receive end plates 112, 118. Thecounterbores 111, 113 do not interfere with the rotor 114 or the oilcontrol valve 116. It should be noted that the internal diameter 110 aof the sprocket housing 110 is smooth prior to forming.

FIG. 12 shows a cross-section of the sprocket housing and end plateprior to orbital riveting and roll forming. The arrow indicates the lineof action of the forming tool. FIG. 13 shows a cross-section of thesprocket housing and end plate prior to roll forming. Because the rollforming tool only applies force vertically, the sprocket edge 115 a ispreferably chamfered to influence displaced material over the coverplate 112. When the end plates 112, 118 are present in the counterbores111, 113 of the housing 110, prior to orbital riveting, the edges oneach side of the sprocket housing 110 each form a lip or flange 115which axially extends further than the end plates 112, 118 when seatedwithin the counterbores 111, 113. The end plates 112, 118 containcutouts or grooves 121 along an outer circumference which receive theflow riveting material, such as peen, during the riveting process. Thecutouts or grooves 121 are preferably V-shaped.

An orbital riveting machine (not shown) may then use a peen which isgradually lowered onto the lip 115 of the housing, spreading thematerial of the rivet, such that the material flows into the grooves 121along the outer circumference of the end plates 112, 118, creatingprojections 119 which complement the cutouts or grooves 121 of the endplates 112, 118, such that a mechanical joint 120 is created between theouter circumference of the end plates 112, 118 and the innercircumference 110 a of the sprocket housing 110. The mechanical jointadditional includes the lip 115 capturing the recessed end plates 112,118 through the bending of the lip 115, retaining the end plates 112,118 to the sprocket housing 110 as shown in FIGS. 14-19.

FIG. 15 shows the V-grooves 121 in outer circumference of the end plate112 which act like a press die forcing the rolled edge of the flange 115and the peen into a triangular shape (projection 119), restricting theend plates ability to rotate. The projections 119 are formed on theinner diameter 110 a of the sprocket housing 110 which was smooth priorto the forming taking place as shown in FIG. 9. The rolling die and theorbital riveting tool (not shown) acts on the flange 115 to forcematerial forward over the end plates 112, 118 forming a captive lip 115as seen in FIGS. 16-19.

The joint 120 formed between the end plate 112, 118 and the housing 110has an increased torque carrying capability as compared to joints formedby a fastening means such as a bolt or screw.

In another embodiment, the roller forming of FIGS. 1-8 may be enhancedby forming grooves in the end plates and using the material and orbitalriveting to further enhance the joint formed for torque transfer.

In an alternate embodiment, orbital riveting as described above may beused to attached an end plate on one side of the housing and rollerforming as describe above may be used to attach an end plate to theother side of the housing.

In another embodiment, orbital riveting as described above may be usedto attach an end plate to one side of the housing and conventional boltsmay be used to attach an end plate to the other side.

In another embodiment, roller forming as described above may be used toattach an end plate to one side of the housing and conventional boltsmay be used to attach an end plate to the other side.

In another embodiment, orbital riveting and roller forming as describedabove may be used to attach other components to the housing or the endplates of the phaser, such as attaching a pulley or a sprocket, the endplates may then be bolted to the phaser.

Accordingly, it is to be understood that the embodiments of theinvention herein described are merely illustrative of the application ofthe principles of the invention. Reference herein to details of theillustrated embodiments is not intended to limit the scope of theclaims, which themselves recite those features regarded as essential tothe invention.

What is claimed is:
 1. A method of retaining a first end plate to afirst side of a sprocket housing of a variable cam timing phaser and asecond end plate to a second side of the variable cam timing phasercomprising the steps of: press-fitting at least the first end plate ofthe phaser into a counterbore defined by at least the first side of thesprocket housing such that a portion of the sprocket housing on thefirst side axially extends past the first end plate to form a first lip;and continuously bending the first lip such that the first lip bends andcaptures the first end plate on the first side of the sprocket housing.2. The method of claim 1, further comprising the steps of: press-fittingthe second end plate into a counterbore defined by the second side ofthe sprocket housing, such that a portion of the sprocket housing on thesecond side of the sprocket housing axially extends past the second endplate to form a second lip; and continuously bending the second lip suchthat the second lip bends and captures the second end plate on thesecond side of the sprocket housing.
 3. The method of claim 1, furthercomprising grooves defined on the first end plate.
 4. The method ofclaim 3, further comprising the steps of: applying peen to the grooveson the first end plate such that the peen additionally joins the firstend plate to the first lip, creating a mechanical joint between thefirst lip and the first end plate.
 5. The method of claim 1, furthercomprising grooves defined on the second end plate.
 6. The method ofclaim 5, further comprising the steps of: applying peen to the grooveson the second end plate such that the peen additionally joins the secondend plate to the second lip, creating a mechanical joint between thesecond lip and the second end plate; and continuously bending the secondlip such that the second lip bends and captures the second end plate onthe second side of the sprocket housing.
 7. The method of claim 1,further comprising the steps of: bolting the second end plate to thesecond side of the sprocket housing by bolts.
 8. The method of claim 1,wherein the continuous bending is carried out by roller forming.
 9. Amethod of retaining a first end plate to a first side of a sprockethousing of a variable cam timing phaser and a second end plate to asecond side of the variable cam timing phaser comprising the steps of:press-fitting at least the first end plate of the phaser into acounterbore defined by at least the first side of the sprocket housingsuch that a portion of the housing on the first side axially extendspast the first end plate to form a first lip; applying peen to grooveson the first end plate such that the peen joins the first end plate tothe first lip, creating a mechanical joint between the first lip and thefirst end plate; and continuously bending the first lip such that thefirst lip bends and captures the first end plate on the first side ofthe sprocket housing.
 10. The method of claim 9, further comprisinggrooves defined on the second end plate.
 11. The method of claim 10,further comprising the steps of: applying peen to the grooves on thesecond end plate such that the peen joins the second end plate to thesecond lip, creating a mechanical joint between the second lip and thesecond end plate; and continuously bending the second lip such that thesecond lip bends and captures the second end plate on the second side ofthe sprocket housing.
 12. The method of claim 9, further comprising thesteps of: bolting the second end plate to the second side of thesprocket housing by bolts.
 13. The method of claim 9, wherein thecontinuous bending is carried out by roller forming.
 14. A variable camtiming phaser comprising: a first end plate received within a firstcounterbore on a first side of a housing assembly, the housing having afirst lip which extends axially from the counterbore, such that thefirst end plate is secured to the housing assembly on the first side byroller forming the first lip relative to the first end plate; and asecond end plate received within a second counterbore on the second sideof the housing assembly.
 15. The variable cam timing phaser of claim 14,wherein the housing has a second lip which extends axially from thecounterbore, such that the second end plate is secured to the housingassembly on the second side by roller forming the second lip relative tothe second end plate.